Looks like a Allen Scythe model T or more likely TS, using the Villiers 25c two stroke engine and “Lightweight” or “junior” carb. Front cowl is missing, so is exhaust, so don’t try to start it! A major restoration job, but not impossible. You will find the original service manuals online if you search, and there are several suppliers of Villiers and Allen parts, but not the gearbox or cutter bar, so it might mean canabalising another machine to get all the bits to make one complete. However, there are still lots of them around.
Good luck, let us know how you get on.
